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EMS 353. EMS 353. Lectures 6 Lectures 6 Dr . Maha KhalidDr . Maha Khalid
physiology of pharmacology cardiovascular system
Coronary Heart DiseaseCoronary Heart DiseaseThe major underlying
cause is atherosclerosisatherosclerosis..AtherosclerosisAtherosclerosis is a
slow, progressive disease which begins in childhood and takes decades to advance
Coronary Heart DiseaseCoronary Heart DiseasePlaque (the build-up of
lipid/cholesterol) in the artery wall forms as a response to injuryinjury to the endothelium in the artery wall.
Coronary Artery Coronary Artery DiseasesDiseases
Due to arterio- and atherosclerosis of the coronary arteries
Fatty plaques cause blockage and decreased blood flow to the myocardium
Main symptom is angina pectoris or chest pain, caused by lack of blood and oxygen
Myocardial infarction (MI) occurs when an artery is totally blocked
atherosclerosis
Atheroma
Artery wall
Blood within the artery
Atheroma (fatty deposits)
building up
Fat deposits develop, restricting blood flow
through the artery
Angina PectorisAngina PectorisChest pain due to coronary artery
disease (CAD) and myocardial ischemia
1.Exertional angina (pain) usually occurs during physical exertion or stress
2.Vasospastic angina may occur at any time and is due to coronary artery vasospasm
Untreated CAD and angina pectoris may lead to myocardial infarction and death
angina and heart attackangina and heart attackangina
◦narrowed coronary artery
◦tightness or ache in the chest, breathlessness, sick feeling, dizziness
◦comes on with exertion or emotion
◦goes away with rest - usually 2-10 mins
heart attack◦due to sudden
blockage of the coronary artery
◦chest pain “like a band”, indigestion, breathlessness, sickness, looking pale
◦comes on at any time
◦doesn’t go away - if still there in 15 minutes call for
emergency
Drugs Used to Treat Drugs Used to Treat CADCAD
Nitrites and nitratesBeta adrenergic blocking drugs
Calcium antagonists, also referred to as calcium channel blockers
Nitrites and NitratesNitrites and NitratesDrugs stimulate the formation of nitric
oxide, a potent vasodilator of blood vessels
Vasodilation of veins and arteries decreases cardiac work and cardiac oxygen consumption to relieve the pain of myocardial ischemia
Nitrites and nitrates may cause a drop in blood pressure and reflex tachycardia
These drugs can be used to treat acute attacks of angina or to prevent anginal attacks
Drugs Used to Relieve Drugs Used to Relieve Acute Attacks of AnginaAcute Attacks of Angina
Amyl nitrite is administered by inhalation from a glass ampule, it has a sudden onset and duration of action of 5–10 minutes
Nitroglycerin is administered as sublingual tablets which require a few minutes for onset and may last 30–45 minutes
Nitroglycerin may also be administered intravenously in more severe cases
Drugs Used Drugs Used Prophylactically to Prophylactically to Prevent Angina PectorisPrevent Angina Pectoris Nitroglycerin can be administered as an ointment, as extended release tablets or capsules, or by transdermal patch
Isosorbide and pentaerythritol nitrates are usually administered orally 3–4 times/day depending on the frequency of anginal
attacks
Adverse Effects of Adverse Effects of Nitrites and NitratesNitrites and Nitrates
Vasomotor flushing, dizziness, and headache are common due to vasodilation
When administered for acute angina, the sudden onset of vasodilation may cause hypotension, fainting, and tachycardia
Patients should be seated when inhaling or taking these drugs sublingually
Myocardial Infarction Myocardial Infarction (MI )(MI )
Caused by complete blockage of one of the coronary arteries
Heart cells deprived of blood/oxygen become ischemic, die, and form an infarct
MI may result in sudden death, or the infarct undergoes a healing process and is replaced with connective tissue
After an MI the heart may be weakened and develop congestive failure or cardiac arrhythmias